You could take the hints of Logrus failures, imperfect Logrus, and various strangenesses of the Abyss and mash them together.
Add tobasco sauce… sorry, copying from Dworkin’s notes here.
We already know there is a pile of skulls outside the entry to the Logrus (I blame Zelazny) and so we can imagine that most forms of imperfect Logrus are even more lethal than Logrus itself. (Red wire? NO BLUE!) After all, even successful Logrus initiates deal with insanity for a long time afterwards.
So cross the streams a bit, look at Umbra from the Lords of Gossamer and Shadows… a power that is guaranteed to make you insane, reveal the flaws in everthing, rewrite you if you receive a near fatal injury, and lose control of your shapeshifting. That sounds like screwed up Logrus to me.
And also, it is so weak that while it looks powerful to all those shadowfolks, it can be dismissed by Logrus or Pattern.
And it cannot even bring you a pizza.
Of course, if you can find a pizza shop, Broken Logrus Masters never have to PAY for pizza.